Abstract

This engineering article presents an original method of building and operating an assistive autonomous mobile robot based on a custom-designed LEGO® structure using Raspberry Pi® Model B computers, Dexter Industries® BrickPi boards, and LEGO NXT peripherals. The robot is programmed using the Python language to detect, identify, and handle objects in places that are inaccessible or dangerous to humans. The robot assists people with limited mobility to find and retrieve hidden or lost objects. The two distinct modes of operation are the assistive autonomous mode, and the exploratory, operator-controlled mode, respectively. In the autonomous mode, the robot moves automatically and uses its pre-programmed input parameters and signals from the ultrasonic sensors and video camera to navigate by avoiding obstacles; upon detecting the target object, the motion ceases, the robotic arm extends, grasps, and retrieves the object. The operator can afterwards direct the robot towards other zones for exploration or object retrieval. In the exploratory mode, the operator controls the movement of the robot and visualizes on a monitor the images continuously sent by the on-board video camera. Future development may consist of implementing the autonomous mode in which objects in motion will be tracked and retrieved.